Air-brake mechanism



4 Sheets-Sheet 1.

(No Model.)

H S HOPPER AIR BRAKE MECHANISM.

Patented June 10, 1890.

v No. 430,024,

4 SheetsSheet 2.

(N0 Model.)

H S HOPPER AIR BRAKE 'MEGHANISM.

Patented June 10, 1890.

(No Model.) 4 Sheets-Sheet 3. H. S. HOPPER.

AIR BRAKE MEGHANISM.

No. 430.024. Patented June 10, 1890.

[WI/M227:

ZVZ' messes.

4 Sheets-Sheet 4.

(No Model.)

H S HOPPER AIR BRAKE MECHANISM. No. 430,024.

Patented June 10, 1890.

MZZ/zmses.

' UNITED STATES PATENT OFFICE.

HENRY S. HOPPER, OF DETROIT, MICHIGAN.

AIR-BRAKE MECHANISM.

SPECIFICATION forming part of Letters Patent No. 430,024, dated June 10,1890.

Application filed November 8, 1889. Serial No. 329,608. (No model.)

To all whom it may concern:

Be it known that I, HENRY S. HOPPER, a

- citizen of the United States, residing at Detroit, county of \Vayne,State of Michigan, have invented a certain new and useful Improvement inAir-l3rake Mechanism; and I declare the following to be a full, clear,and exact description of the invention, such as will enable othersskilled in the art' to which it pertains to make and use the same,reference being had to the accompanying drawings, which form a part ofthis specification.

In the drawings, Figure 1 is a sectional View illustrating my invention.Fig. 2 is an end elevation with parts removed, looking against the endof the auxiliary air-reservoir. Fig. 3 is a sectional view on the line xas of Fig. 1. Fig. 4 is a view similar to Fig. 1, but illustratingmechanism for neutralizing the effects of jogs and jars upon thecar-springs incident to their ordinary use and means for recharging theauxiliary reservoir while the brakes are set or partially set. Fig. 5 isa view of the dash-pot mechanism hidden from View in Fig. 4:. Figs. 6,7,8, 9, and 10 are diagrammatic views showing the operation of themechanism under varying conditions. Fig. 6 shows the position of theparts when starting to charge the auxiliary air-reservoir andtrain-pipe. Fig. 7 shows their position when the pressure in thetrain-pipe has reached its maximum, that in the auxiliary air-reservoirhaving reached the lower pressure adequate for its car when empty andhaving cut off further pressure. Fig. 8 shows the same when pressure inthe train-pipe has been relieved to set the brakes for a service stop.

Fig. 9 shows the position of the parts corresponding to Fig. 6, exceptthat the car having been partially loaded the fulcrum of thegoverning-lever has been shifted to correspond, with this change ofload. shows the same with the fulcrum automatically shifted tocorrespond with a maximum load on the car.

My invention has for its object to produce an air-brake for any cars,and more particularly one adapted specially for freight-cars, whereinthe load varies widely from that of an empty car to the same with itsmaximum load; also, to produce means whereby the Fig. 10

auxiliary air reservoir may be recharged while the brakes are set; also,to provide means whereby the usual flexing of the carsprings, due to theroughness of the road in ordinary transit, maybe neutralized, so as notto affect the air-brake mechanism nor change the adjustment .it hasautomatically taken corresponding with the load the car is carrying;also, in the provision of means whereby the apparatus may be adjusted atwill on any car to conform to the particular range of motion to whichits springs are subjected from its empty to its loaded condition, andthat the mechanism governing the admission of air to the auxiliaryair-reservoirshall be at its proper adjustment, conforming to anunloaded car even though the springs of different cars may, when empty,stand at difierent degrees of compression, and other features ofconstruction.

In carrying out myinvention, A represents the auxiliary air-reservoir;B, the pipe or conduit leading to the brake cylinder. (Not shown.)

O is the body of the car on which the apparatus is applied.

O is the transom or other stationary part of the truck-frame. To one ofthese parts-- 1'. e., the truck or body bolster, but preferably thebody-bolster-is supported at its fulcrum c a lever O One of its arms isengaged with the other part through the medium of a link at c. The otherend of this lever is engaged with the connecting rod or bar 0 whichunites it with the arm d of the lever D. There is a helical or otherspring 0 on the line of the rod 0 and a turn-buckle O and one of thearms of the lever O is slotted at 0 The lever D is fulcrumed at d, andits free end d constitutes the movable fulcrum of another lever E. Thislever E is at one end engaged with the small piston F and at its otherend with the large piston G.

H is the conduit connecting with the trainpipe.

I will now describe the operation of the primary partsof the apparatus.

We will suppose, for instance, that the area of the large piston G isjust twice that of the small piston F, and there is no pressure at allin the train-pipe. The moment pressure begins it acts upon the smallpiston F to bring all the parts to the position shown in Fig. 6,1" beingopen, the passages from the auxiliary reservoir to the brake-cylinderclosed, and the brake-cylinder open through f and the valve I, with theexhaust-port I. Now the engineer proceeds to establish a normal pressurein the train-pipe of, say, sixty pounds. As the pressure accumulates,the air passes throughf, thence through f and f and into the auxiliaryreservoir A. It is manifest that the pressure in the ante-chamber A isalways the same as in the auxiliary reservoir. It accumulates morerapidly outside the small piston F, because it has to pass hence throughthe restricted orifice f. Soon, however, a pressure of, say, sixtypounds has accumulated in front of F, while in the auxiliary reservoir Aand antechamber A it has reached, say, twenty pounds. \Ve then have adirect pressure in front of the piston F of sixty pounds and twentypounds backward from within, or a preponderance of but forty pounds fromin front. It will be observed, however, that the twenty pounds ofpressure in the ante-chamber is pressing the piston G with twice theforce that it is acting on the back side of the piston F, or with fortypounds of energy, and this by the lever D is transmitted also to theback of F, and added to the twenty pounds of air-pressurejustneutralizes or comes to an equilibrium with the pressure fromthetrain-pipe. The further admission of air through the port f causesthe piston Gto move forward and so presses out the pistonFand closes theport f. \Ve therefore now have the parts again at rest, as shown in Fig.7,'and with sixty pounds in the trainpipe and only twenty in theauxiliary airreservoir with which to operate the brakes. Now suppose wewant to make a service stop or check slightly on a downgrade. Air ispermitted to escape somewhat from the trainpipe. This causes the outwardpressure on the back of F to preponderate. The piston is forced out,opening only the small orifice f for air to pass from the auxiliaryreservoir to the brake-cylinder. The relief thus afforded soonreestablishes an equilibrium back of and in front of F, and as soon asthe pressure in front preponderates the piston recedes and opens theport f. The valve I, however, has a little play, as shown at 2', and asthe piston F recedes gradually it finally overtakes and moves the valveI just enough to close the passage f without opening the brake-cylinderto the exhaust, and the pressure is permitted to again accumulate in theauxiliary reservoir while the brakes are yet set. As soon as anequilibrium is again established with the reduced pressurein the pipethe piston F is forced out and closes off the port f without moving thevalve I. Now, to release the brakes, pressure in the train pipe isbrought up suddenly in the usual way, which operates to foree-the pistonF quickly backward to its full stroke, and this carries the remain inthe train-pipe.

valve I to a point where it opens the brakecylinder to the exhaust I andbrings all the parts to the position shown in Fig. (5.

D is a dash-pot, within which plays the plunger D which is connectedwith the lever 1). Its purpose is to prevent any sudden motion orvibration of the leverD, due to the jolting of the car, and compellingthe spring (l to yield to accommodate these vibrations, which is thefunction of the said spring.

G is a vent-orifice, and g a valve adapted to open freely when thepiston G is forced inwardly by pressure from the chamber A, and g is asmall orifice, through which air may enter slowly when the preponderanceof pressure is in front of the piston F, and so permitting the piston Gto return slowly to its initial position. Thus a dash pot is formed, andthe connection with the piston F causes the latter to retract with thesame reduced speed as the piston G.

In line with the piston F is a spring beyond it. It is apparent thatwhen this spring is compressed the valve is open, and air fromthetrainiiipemay escape through ports j to the exterior. This valve isupon its exterior constructed to form adash-pot, and on the (lash-potrod J is a spring J which operates in aid of the spring J to hold thevalve J closed against its seat. Now for a service stop the engineerrelieves slightly the pressure in the train-pipe. which brings theprojection from the piston F to or nearly to the dash-pot rod J but whenhe wishes to make an emergency stop he wishes to stop as quickly aspossible. He therefore relieves as much as he can his train-pipe. Thiscauses the piston F to come back to the end of its stroke, and, added towhatever pressure may yet remain in the train-pipe, the valve J isforced from its seat, and the pressure in the train-pipe is stillfurther relieved at this point without the air having to pass backthrough the train-pipe. As soon, however, as the pressure has been thusrelieved by forcing in the dash-pot rod, the air in the dash-potnaturally escaping past the plunger under the influence of the spring J,the valve J is again closed on its seat and so stops further escape fromthe train-pipe and saves whatever degree of pressure may yet As soon aspressure is again accumulated in front of the piston F it is forcedbacluvard, the dash-pot rod resuming its initial position and its springJ 3 acts to assist the spring J to hold the valve to its seat, the twobeing ample to hold it closed against the maximum pressure in thetrain-pipe. This mechanism also serves as a safety-valve to prevent anyunduly great pressure in the train-pipe should its pressuregovernorbecome disordered.

I will now describe how the apparatus is designed to changeautomatically to correspond with dilferentloads on the car. It will beobserved that by shifting the fulcrum d on the lever E toward or fromthe piston G this piston will react with correspondingly IIO less orgreater energy against the back of the piston F. So, also, it will beobserved that weight or load added to the oarwill act to pull the rodand lever D, and so serve to shift the fulcrum d toward the piston G,while removing the load will operate to shift it toward the piston F.Now, to effect the proper adjustment of the parts, we will suppose thatin 1 the instance illustrated it requires a working-pressure in theauxiliary reservoir of twenty pounds in order to set the brakes on thecar when empty without causing its wheels to slide on the track. Underthese conditions the rod 0 isby the turn-buckle C or otherwise, soadjusted that the fulcrum 01 shall be at the middle of the lever E whenthe car is empty. Now When the car has been loaded to its maximum theengagement at the slot 0 in the lever C is so adjusted that the fulcrum(1 shall then rest at a point on the lever E nearer to the piston Gr,which will just brake the wheels without permitting them to slide. It isnow evident that with variations of the load between these limits thesaid fulcrum (1 will be automatically shifted to correspond therewith;and, finally, it is obvious that the heavier the load the nearer is thefulcrum d shifted toward the piston G, and the greater the amount ofpressure required to accumulate in the ante-chamber A before it willoperate to neutralize that on the piston F and cause the latter to moveout and cut off the port f, and so automatically graduating theworkingpressure in the auxiliary chamber to correspond with the load onthe car at all times.

I do not wish to limit myself in every in-v stance to constructionswhich shall possess each and every one of the features which I havedescribed or illustrated. Thus, for instance, the spring in the red Clnight be dispensed with, although I prefer to employ it, or some otheryielding element might be introduced at this or some other point in theconnections for a like purpose. So, also, the turn-buckle may bedispensed with or another means of adjustment be provided. Again, thedash-pots, while they conduce to any easy and cushioned action, are notabsolutely essential, though preferable, for other yielding resistancesmight be employed. Other minor details may also be varied withoutdeparting from the spirit of my invention. and I would have itunderstood that instead of the single brake-valve the common form ofmain and auxiliary valves at this point might be employed.

The pistons F and G maybe of any desired relative sizes with respect toeach other. In the foregoing description the piston G has been, forconvenience of description only, presumed to be of twice the area of thepiston F but the relative sizes may be varied to any desired extent.

What I claim is- 1. In an air-brake mechanism, the combination, with thetrain-pipe, auxiliary reservoir, brake-cylinder, andtriple-valve-operating piston, of valve mechanism connected with saidpiston, whereby the pressure in the auxiliary reservoir is automaticallyvaried to correspond with the variations of the load upon thecar-trucks, substantially as described. 2. In an air-brake mechanism,the combination, with the train-pipe, auxiliary reservoir,brake-cylinder, and triple-valve-operat ing piston, of a valve mechanismconnected with said piston, whereby the pressure in the auxiliaryreservoir is automatically maintained at the proper degree to insurethat the pressure on the brake-shoes shall always bear the properrelation to the weight of the car whether it be light or loaded to anydegree, substantially as described.

3. In an air-brake mechanism, the combination, wit-h the train-pipe,auxiliary reservoir, brake -cylinder, and triple-valve-operating.piston, of valve mechanism connected with said piston for changing therelative pressures in the train-pipe and auxiliary reservoir, and meanswhereby said changes are automatically effected to conform to the loadby the variation in the space between the body of the car and thestationary part of its truck due to the compression of the springs undervariations of load upon the car, substantially as described.

t. The combination, with an air-brake mechanism, of a piston actuated bydirect pressure from the train-pipe governing the admission of airthrough a port leading to the auxiliary reservoir, another piston beyondsaid port actuated by the air that has passed through the port, and alever connecting the back of the first with the front of the secondpiston, whereby the direct action of the second piston is transmittedagainst the back of the first piston, substantially as and for thepurposes described.

5. The combination, with an air-brake mechanism, of a direct-pressurepiston governing the air-port to the auxiliary reservoir, a pistonbeyond said port actuated by air that has passed through the port, aconnecting-lever, and an adjustable fulcrum, with means adapted to shiftsaid fulcrum along the connecting-lever, whereby the second piston iscaused to exert a greater or less pressure againstthe first piston,substantially as and for the purposes described.

6. The combination, with an air-brake mechanism, of a piston governingthe port to the auxiliary reservoir, a piston beyond said port, and aconnecting-lever with an adjustable fulcrum, of a lever fulcrumed on thecar with one of its arms engaged with the truck, said lever connectedwith the said movable fulcrum, whereby the relative depression of thecar on its springs due to variations in the load operates through saidintermediate connections to automatically shift the said fulcrum in acorresponding degree, substantially as described.

7. The combination, with the two pistons,

connecting-lever, ad j ustable'f ulcru m, and the lever engaging the.car and its truck with intermediate connections, of the slotv' and link,whereby the throw of said last-named lever may be adjusted to shift theadjustable 'l'ulcru 111 through the proper range corresponding with noload and a maximum load on the car, substantially as described.

8. The combination, with the two pistons, their connecting-lever, andair-port f to the auxiliary reservoir, of a valve governing the ports fand f to the brake'eylinder, said valve having play, substantially asdescribed, with respect to the piston 1 whereby the piston may be movedto close the passages from the auxiliary reservoir to the brake-cylinderand to open the port f without opening the brake-cylinder to theexhaust, thereby permitting the engineer to recharge the auxiliaryreservoir while the brakes are set, substantially as described.

9. The combination, with the two pistons, their connecting-lever, theadjustable fulcrum, and its automatical shitting mechanism, of ayielding resistance and a spring in the connections between the ear andthe said fulcruxmwhereby vibrations of the car-spri ngs, due to theusual roughness of the railway track, is compensated without shiftingsaid fulcrum, substantially as described.

10. The combination, with an air-brake mechanism, of a valve governingthe portfrom the train-pipe to the auxiliary reservoir and adapted,also, to actuate the valve meclr anism governing the port or portsthrough which the air is admitted from the auxiliary reservoir to thebrake-cylinder in the manner described, and in connection with saidfirst valve a yielding resistance, as G G, whereby,

when it has been advanced to set the brakes, it is caused to returnslowly, thereby shifting said second valve mechanism to close itsadmission-port without driving it far enough to open the exhaust and atthe same time opening the port from the train-pipe to the auxiliaryreservoir, whereby the latter may be recharged while the brakes are yetset, substantially as described.

11. The combination, with an air-brake mechanism, of a valve governingthe port to the auxiliary reservoir, a brake-cylinder valve associatedwith and operated by the firstnamcd valve in the manner described, andyielding resistance, as G G, for retarding the return motion of thefirst valve after the brakes are set, as explained, the same consistingof a dash-pot and valve, whereby it is free in its initial movement andrestricted in its return movement, substantially as and for the purposesset forth.

12. The combination, with an air-brake mechanism, of means for providinga local escape from the train-pipe in an el'nergeney stop, the sameconsisting of the dash-pot valve and springs J J said plunger adapted tobe actuated by a moving part when making an emergency stop to open thevalve, after which the valve is closed by one of the springs andsubsequently aided by the other spring to hold it closed, substantiallyas and for the purposes described.

In testimony whereof I signed this specification in the presence of twowitnesses.

HENRY S. HOPPER. \YitnesSes:

l1. umen, \V. W. LEGGETT.

